The introverted science teacher who acts like a cultist. She has a personality similar to that of Chikage from Sister Princess except that she is far more interested in science and things that can be explained through science. Though she usually comes across as 'emotionless', Kisaragi is an incredibly warm, loving, sweet and kind-hearted person who is fond of cute things (such as baby animals, pink pajamas and her son), and cares deeply for the people around her.
The school nurse and miko (meaning priestess), Yayoi can be calm and spiritual unless she feels Chitose is in danger, when she may put her sword fighting skills to work. She is seen wearing a Japanese priest dress and puts her sword against Chitose's neck in order to attain a positive response.
A mysterious kid from China who claims to be the rightful child of Mutsuki. She first appears in Happy Lesson Advance. She is very well versed in Kung Fu, and contends with Chitose at every chance possible. Despite that fact that she is first introduced wearing a red China dress, she prefers to dress like a boy. Not only that, but she apparently enough, is a huge fan of Hazuki Yazakura.
Our heroine, Ruu MACHIDA, is having a hard time. Her mother died when she was little, and her father, with whom she had been living, has disappeared without a trace after getting into debt. Ruu is on her own. To make ends meet, she takes a job as a live-in maid for a very wealthy household. To Ruu's surprise, the house she ends up working at is the home of three cute brothers, and she already knows one of them! They agree to let Ruu work there because they are often alone and they could use the help. Their parents are often away on business. Ruu moves in and works hard as a maid, and they all become very close. But things aren't always smooth sailing. Ruu has a lot of pressure on her because of her father's debts, and three very cute guys to deal with!
The student council president. He and his parents own a flower shop. He is Yasuaki's best friend
Yukisaki Eri is a beautiful high school girl who fights a mysterious hooded chainsaw-wielding man in the night in order to uphold justice.
Yusake's best friend who died in a tragic accident.